Complete the sentences: 1. Mary is (young) then Tom. 2. My grandfather is (old) than my grandmother. 3. This box is the

 1. Mary is younger than Tom. 2. My grandfather is older than my grandmother. 3. This box is the heaviest of all. 4. Her hair is lighter than his. 5. Oleg is the tallest of all in our class. 6. My sister is smaller than his. 7. Our house is the biggest in our street. 8. This book is more interesting than that, but this one is the most interesting. 9. A mouse is smaller than a cat. 10. This dress is more expensive that one, but this is the most expensive of all.